Factual error: The Legends are stranded in England and wait for a bus to London. However, the bus that pulls up is left-hand drive, when it should be a right-hand drive one.
Left Behind - S1-E9
Plot hole: It's revealed that Chronos is Mick from the future after he was abandoned by Snart. However, in the episode White Knights (episode 4) the earlier version was able to sneak up on Chronos and surprise him with an attack from behind. If that was a future version of Mick then surely he would have remembered the attack coming and could not have been so easily caught off guard.
Last Refuge - S1-E12
Factual error: In 1993, when Jefferson's father James comes to the hospital to see his son after he is born before he deploys to Somalia, he is wearing his rank upside down on his uniform collar, and he has no rank on his headgear. Also, he wore his headgear while he was indoors for the duration of the episode. Headgear is not authorized to be worn while indoors except in certain cases, none of which would have applied while he was in the hospital visiting his son. (00:18:15)
Continuity mistake: When Sara rejoins the crew at the end of the episode, Nate lifts his left hand to his face and hollers. In the next shot, he has his right hand to his face instead. (00:40:25)
Swan Thong - S5-E15
Continuity mistake: During the fight scene near the end when Marie Antoinette tries to stab Mick he grabs her wrist, it keeps changing which wrist he is holding. When it shows from her point of view looking down he has her right, but from his point of view looking up he is holding her left.
Continuity mistake: In the flashback to 1920, Kendra flips the calendar to October with a snowy mountain side picture. Later when she's talking to Carter about leaving, the calendar is now on September with a trail through the grass picture. It goes back to October when their son comes in.
Other mistake: When the 3 go to Ivy Town, "Disco Inferno" is playing. However, this is 1975 and the song was recorded and released in 1976.
Factual error: The quiz on the cereal box asks "who is the most prolific serial killer in the United States", to which Ava replies "Ted Bundy. Although in my opinion, John Wayne Gacy had way more victims than he confessed to." The box also lists Bundy and Gacy (plus the anachronism). 2 things, Gacy was in fact convicted of more murders than Bundy, making him more prolific. But, Samuel Little is the most prolific serial killer in the US and Gary Ridgway is the second. Ted Bundy would rank 6th on most list.
Hey, World! - S4-E16
Continuity mistake: After Gary says "it's part of the show" and turns to face the dragon, he lowers the microphone offscreen. Cut to the front, and it's up by his mouth again.
Answer: My speculation... As Chronos was sent by the Time Masters, the armour he is given may have some sort of 'time folding preventive' system built into it? (A pure assumption on my part).